Nanocoating-konjac enriched natural antimicrobials to maintain the quality of Siam Kintamani oranges at various ripeness

Luh Suriati; I Gusti Bagus Udayana; Ni Made A. S. Singapurwa; I. Putu Candra; I. Wayan Widiantara Putra; Putu Ajus Raditya

Luh Suriati

, I Gusti Bagus Udayana, Ni Made A. S. Singapurwa, I. Putu Candra, I. Wayan Widiantara Putra, Putu Ajus Raditya

Abstract: Siam Kintamani oranges (Citrus nobilis Tan) are gaining popularity among consumers due to their nutritional content and health benefits. However, their quality deteriorates rapidly postharvest, necessitating effective postharvest handling techniques. This study explores using konjac nanocoating enriched with natural antimicrobial agents to maintain the fruit's quality at various ripeness stages. The konjac nanocoating, made from konjac glucomannan and infused with essential oils such as thyme, clove, and cinnamon bark, was tested using a dipping method. The research comprised characterizing the fruit based on ripeness, applying the konjac nanocoating, and analyzing the structure and properties of the coating using a scanning electron microscope. Observed variables included water content, degree of acidity, vitamin C, total dissolved solids, total microbes, color, and texture. Results indicated that applying konjac nanocoating enriched with antimicrobial agents significantly extended the shelf life and preserved the quality of Siam Kintamani oranges. The findings suggest that konjac-based nanocoating enriched with natural antimicrobial clove oil can serve as an innovative solution for enhancing the quality and shelf life of Siam Kintamani oranges, considering the critical maturity stage of 28 weeks. This research provides new insights into natural preservation methods that can reduce reliance on synthetic preservatives, thereby supporting sustainability in the agricultural and food industries. The success of the konjac nanocoating application is highly dependent on the fruit's ripeness stage, which affects its effectiveness in minimizing damage and maintaining quality during storage.

Keywords: Kintamani; konjac; nanocoating; shelf life; Siamese orange

Citation: Suriati, L., Udayana, I. G. B., Singapurwa, N. M. A. S., Candra, I. P., Putra, W. W. & Raditya, P. A. (2026). Nanocoating-konjac enriched natural antimicrobials to maintain the quality of Siam Kintamani oranges at various ripeness. Bulg. J. Agric. Sci., 32(2), 391–403

References: (click to open/close)

Ahmad, M. M., Qureshi, T. M., Zia, M., Mushtaq, M., Iqbal, M. W., Cacciotti, I., Esatbeyoglu, T. & Korma, S. A. (2024). Analytical study to measure the variability in quality factors attenuating the export of Kinnow/Mandarin fruit. Measurement: Food, 14(November 2023), 100155. https://doi.org/10.1016/j.meafoo.2024.100155.
Aini, N., Dwiyanti, H., Setyawati, R., Handayani, I., Septiana, A. T., Sustriawan, B. & Aena, D. A. Q. (2022). Siam orange (Citrus nobilis L.) nectar characteristics with variations in stabilizer and sucrose level. Food Research, 6(3), 315 - 323. https://doi.org/10.26656/fr.2017.6(3).386.
Alshallash, K. S., Sharaf, M., Abdel-Aziz, H. F., Arif, M., Hamdy, A. E., Khalifa, S. M., Hassan, M. F., Abou ghazala, M. M., Bondok, A., Ibrahim, M. T. S., Alharbi, K. & Elkelish, A. (2022). Postharvest physiology and biochemistry of Valencia orange after coatings with chitosan nanoparticles as edible for green mold protection under room storage conditions. Frontiers in Plant Science, 13(November), 1 - 15. https://doi.org/10.3389/fpls.2022.1034535.
Baldassi, C., Lee, C., Dossett, M. & Castellarin, S. D. (2024). High-throughput color determination of red raspberry puree and correlation of color parameters with total anthocyanins. Plant Methods, 20(1), 1 - 13. https://doi.org/10.1186/s13007-024-01197-0.
Basaglia, R. R., Pizato, S., Santiago, N. G., Maciel de Almeida, M. M., Pinedo, R. A. & Cortez-Vega, W. R. (2021). Effect of edible chitosan and cinnamon essential oil coatings on the shelf life of minimally processed pineapple (Smooth cayenne). Food Bioscience, 41.
Bintoro, V. P., Dwiloka, B., Ekaputri, H. & Kamil, R. Z. (2024). The effect of gelatin and konjac glucomannan concentrations on moisture content, water activity, texture, density, and protein content in synbiotic marshmallows. Food Research, 8(4), 409 - 419. https://doi.org/10.26656/fr.2017.8(4).623.
Butler, J., Morgan, S., Jones, L., Upton, M. & Besinis, A. (2024). Evaluating the antibacterial efficacy of a silver nanocomposite surface coating against nosocomial pathogens as an antibiofilm strategy to prevent hospital infections. Nanotoxicology, 18(4), 410 - 436. https://doi.org/10.1080/17435390.2024.2379809.
Chinchkar, A. V., Singh, A., Singh, S. V., Mazumder, K., Bishnoi, M. & Kamble, M. G. (2025). Application and toxicological study of polyvinyl acetate (PVAc) coating on lemon (Citrus limon L.) fruit to extend the shelf life. Journal of Future Foods, 5(2), 145 - 152. https://doi.org/10.1016/j.jfutfo.2024.05.003.
De Bruno, A., Gattuso, A., Ritorto, D., Piscopo, A. & Poiana, M. (2023). Effect of Edible Coating Enriched with Natural Antioxidant Extract and Bergamot Essential Oil on the Shelf Life of Strawberries. Foods, 12(3). https://doi.org/10.3390/foods12030488.
Díaz-Montes, E. & Castro-Muñoz, R. (2021). Edible Films and Coatings as Food-Quality Preservers: An Overview. https://doi.org/10.3390/foods10020249.
Dini, I. (2022). Contribution of Nanoscience Research in Antioxidants Delivery Used in Nutricosmetic Sector. Antioxidants, 11(3), 563. https://doi.org/10.3390/antiox11030563.
Dong, Y., Wei, Z., Yang, R., Zhang, Y., Sun, M., Bai, H., Mo, M., Yao, C., Li, H. & Shi, L. (2023). Chemical Compositions of Essential Oil Extracted from Eight Thyme Species and Potential Biological Functions. Plants, 12(24). https://doi.org/10.3390/plants12244164.
Gao, Y., Kan, C., Wan, C., Chen, C., Chen, M. & Chen, J. (2018). Quality and biochemical changes of navel orange fruits during storage as affected by cinnamaldehyde -chitosan coating. Scientia Horticulturae, 239(May), 80 - 86. https://doi.org/10.1016/j.scienta.2018.05.012.
Garcıá-Pastor, M. E., Garrido-Auñón, F., Puente-Moreno, J., Valero, D. & Serrano, M. (2024). Characterization of maturity stages in blood oranges: external and internal parameters. Acta Horticulturae, 1399, 315 - 322. https://doi.org/10.17660/ActaHortic.2024.1399.39.
Ghosh, T., Nakano, K., Mulchandani, N. & Katiyar, V. (2021). Curcumin loaded iron functionalized biopolymeric nanofibre reinforced edible nanocoatings for improved shelf life of cut pineapples. Food Packaging and Shelf Life, 28(May 2020), 100658. https://doi.org/10.1016/j.fpsl.2021.100658.
Gu, X., Li, J., Yang, L., Liu, L., Li, T., Zhang, H., Gao, Y. & Xiao, L. (2024). Comparative study on the different edible coatings loaded with fennel essential oil/β-cyclodextrin microcapsules for blueberry preservation. Journal of Horticultural Science and Biotechnology, 99(5), 584 - 596. https://doi.org/10.1080/14620316.2024.2318569.
Ha, T. T. N., Pham, T. T., Dam, S. M. A. I., Mac, X. H. O. A., Nguyen, L. P. L., Hitka, G. & Zsom, T. (2023). Effect of 1-methylcyclopropene treatment on quality of ‘Zebra’ apricot harvested at different maturity stages. Progress in Agricultural Engineering Sciences, 19, 69 - 76. https://doi.org/10.1556/446.2023.00084.
Habibi, F., Ramezanian, A., Guillén, F., Castillo, S., Serrano, M. & Valero, D. (2020). Changes in bioactive compounds, antioxidant activity, and nutritional quality of blood orange cultivars at different storage temperatures. Antioxidants, 9(10), 1 - 15. https://doi.org/10.3390/antiox9101016.
Harsojuwono, B. A., Arnata, I. W., Hartiati, A., Setiyo, Y., Hatiningsih, S. & Suriati, L. (2022). The Improvement of the Modified Starch—Glucomannan—Polyvinyl Alcohol Biothermoplastic Composite Characteristics With Polycaprolactone and Anhydride Maleic Acid. Frontiers in Sustainable Food Systems, 6(March), 1 - 13. https://doi.org/10.3389/fsufs.2022.844485.
Hu, X., Saravanakumar, K., Sathiyaseelan, A. & Wang, M. H. (2020). Chitosan nanoparticles as edible surface coating agent to preserve the fresh-cut bell pepper (Capsicum annuum L. var. grossum (L.) Sendt). International Journal of Biological Macromolecules, 165, 948 - 957. https://doi.org/10.1016/J.IJBIOMAC.2020.09.176.
Ismael, F. N. & Hadi, S. T. (2024). The Effect of thyme, rosemary, and lemongrass oils on extension of the shelf life and qualitative characteristics of Iraqi soft cheese. Functional Foods in Health and Disease, 14(1), 1 - 13. https://doi.org/10.31989/ffhd.v14i1.1262.
Khefifi, H., Selmane, R., Mimoun, M. B., Tadeo, F., Morillon, R. & Luro, F. (2020). Abscission of Orange Fruit (Citrus sinensis (L.) Osb.) in the Mediterranean Basin Depends More on Environmental Conditions Than on Fruit Ripeness. Agronomy, 10(4). https://doi.org/10.3390/agronomy10040591.
Kowalewska, A. & Majewska-smolarek, K. (2023). Eugenol-Based Polymeric Materials — Antibacterial Activity doses for long periods of time. Therefore, a growing interest in eu Keywords : essential oils of cinnamon, bay and tulsi leaves, turmeric, nutm Syzygium aromaticum activities of this compound. Antibiotics, 12(11), 1570.
Kumar, N., Pratibha, Neeraj, Ojha, A., Upadhyay, A., Singh, R. & Kumar, S. (2021). Effect of active chitosan-pullulan composite edible coating enrich with pomegranate peel extract on the storage quality of green bell pepper. LWT, 138, 110435. https://doi.org/10.1016/J.LWT.2020.110435
Li, M., Yu, H., Xie, Y., Guo, Y., Cheng, Y., Qian, H. & Yao, W. (2021). Effects of double layer membrane loading eugenol on postharvest quality of cucumber. LWT, 145.
Lon Kan, E. E., Sargent, S. A., Cantliffe, D. J., Berry, A. D. & Shaw, N. L. (2019). Harvest maturity and storage temperature affect postharvest quality of ‘wanda’ datil hot pepper grown under protected culture. Hort Technology, 29(4), 402 - 407. https://doi.org/10.21273/HORTTECH04328-19.
Lu, W., Chen, M., Cheng, M., Yan, X., Zhang, R., Kong, R., Wang, J. & Wang, X. (2021). Development of antioxidant and antimicrobial bioactive films based on Oregano essential oil/mesoporous nano-silica/sodium alginate. Food Packaging and Shelf Life, 29.
Lugaresi, A., Steffens, C. A., Heinzen, A. S., Fenili, C. L., Brighenti, A. F., de Martin, M. S. & do Amarante, C. V. T. (2024). The influence of the summer pruning on ‘Fuji’ apples storage under controlled atmosphere. Acta Scientiarum - Agronomy, 46(1), 1 - 13. https://doi.org/10.4025/actasciagron.v46i1.63557.
Mohammed, M., Alqahtani, N. K. & Ali, S. A. (2024). Development, RSM-based modeling, and process optimization of an ultrasonic coating system for extending the storage life of fresh fruits. Frontiers in Sustainable Food Systems, 8(June). https://doi.org/10.3389/fsufs.2024.1403164.
Mousavian, D., Mohammadi Nafchi, A. & Nouri, L. (2021). Effect of active packaging based on polyethylene/propylene films containing thymol on the quality attributes and shelf life of season salad. Journal of Food Science and Technology (Iran), 18(116). https://doi.org/10.29252/FSCT.18.07.06.
Nasrin, T. A. A., Rahman, M. A., Arfin, M. S., Islam, M. N. & Ullah, M. A. (2020). Effect of novel coconut oil and beeswax edible coating on postharvest quality of lemon at ambient storage. Journal of Agriculture and Food Research, 2, 100019. https://doi.org/10.1016/J.JAFR.2019.100019.
Ngoc, L. S., Van, P. T. H., Nhi, T. T. Y., Dung, N. A. & Manh, T. D. (2022). Effects of dipping time in chitosan (CS) and polyvinyl alcohol (PVA) mixture to quality of orange fruits during storage. Food Science and Technology (Brazil), 42, 1 - 7. https://doi.org/10.1590/fst.114221.
Nunes, C., Silva, M., Farinha, D., Sales, H., Pontes, R. & Nunes, J. (2023). Edible coatings and future trends in active food packaging–fruits’ and traditional sausages’ shelf life increasing. Foods, 12(17), 3308.
Ochoa-Velasco, C. E., Pérez-Pérez, J. C., Varillas-Torres, J. M., Navarro-Cruz, A. R., Hernández-Carranza, P., Munguía-Pérez, R., Cid-Pérez, T. S. & Avila-Sosa, R. (2021). Starch edible films/coatings added with carvacrol and thymol: In vitro and in vivo evaluation against colletotrichum gloeosporioides. Foods, 10(1). https://doi.org/10.3390/foods10010175.
Perdana, M. I., Ruamcharoen, J., Panphon, S. & Leelakriangsak, M. (2021). Antimicrobial activity and physical properties of starch/chitosan film incorporated with lemongrass essential oil and its application. LWT, 141.
Pernin, A., Bosc, V., Maillard, M. N. & Dubois-Brissonnet, F. (2019). Ferulic acid and eugenol have different abilities to maintain their inhibitory activity against Listeria monocytogenes in emulsified systems. Frontiers in Microbiology, 10(FEB). https://doi.org/10.3389/FMICB.2019.00137.
Pham, T. T., Nguyen, L. L. P., Dam, M. S. & Baranyai, L. (2023). Application of Edible Coating in Extension of Fruit Shelf Life: Review. AgriEngineering, 5(1), 520 - 536. https://doi.org/10.3390/agriengineering5010034.
Radi, M., Akhavan-Darabi, S., Akhavan, H.-R. & Amiri, S. (2018). The use of orange peel essential oil microemulsion and nanoemulsion in pectin-based coating to extend the shelf life of fresh-cut orange. Journal of Food Processing and Preservation, 42(2). https://doi.org/10.1111/jfpp.13441.
Reyes, L. M., Landgraf, M. & Sobral, P. J. A. (2021). Gelatin-based films activated with red propolis ethanolic extract and essential oils. Food Packaging and Shelf Life, 27, 100607.
Shenbagam, A., Kumar, N., Rahul, K., Upadhyay‬, A., Gniewosz, M. & Kieliszek, M. (2023). Characterization of Aloe Vera Gel-Based Edible Coating with Orange Peel Essential Oil and Its Preservation Effects on Button Mushroom (Agaricus bisporus). Food and Bioprocess Technology, 16(12), 2877 - 2897. https://doi.org/10.1007/s11947-023-03107-z.
Strano, M. C., Restuccia, C., De Leo, R., Mangiameli, S., Bedin, E., Allegra, M., Quartieri, A., Cirvilleri, G. & Pulvirenti, A. (2021). Efficacy of an antifungal edible coating for the quality maintenance of Tarocco orange fruit during cold storage. Crop Protection, 148(May), 105719. https://doi.org/10.1016/j.cropro.2021.105719.
Suarez-Barreiro, J. M., Suarez, M. C., Calvo, M. A., Parada, F., Cortés, F., Tobón, F. & Toro, S. (2024). Screening of essential oils against oxacillin-resistant Staphylococcus aureus strains isolated from bovine mastitis. Boletin Latinoamericano y Del Caribe de Plantas Medicinales y Aromaticas, 23(3), 401 - 409. https://doi.org/10.37360/blacpma.24.23.3.28.
Suhag, R., Kumar, N., Petkoska, A. T. & Upadhyay, A. (2020). Film formation and deposition methods of edible coating on food products: A review. Food Research International, 136(March), 109582. https://doi.org/10.1016/j.foodres.2020.109582.
Suriati, L. (2023). Nanocoating-konjac application as postharvest handling to extend the shelf life of Siamese oranges. Frontiers in Sustainable Food Systems, 7, 1104498. https://doi.org/doi: 10.3389/fsufs.2023.1104498.
Suriati, L. & Mangku, I. G. P. (2023). Application of coating-konjac to maintain the quality of Kintamani Siamese oranges during storage. IOP Conference Series: Earth and Environmental Science, 1228(1), 012009. https://doi.org/10.1088/1755-1315/1228/1/012009.
Suriati, L., Utama, I. M. S., Harsojuwono, B. A., Gunam, I. B. W., Adnyana, I. M. & Fudholi, A. (2021). Nano-ecogel to maintain the physicochemical characteristics of fresh-cut mangosteen. AIMS Agriculture and Food, 6(4), 988 - 999. https://doi.org/10.3934/agrfood.2021059.
Xiao, M., Luo, L., Tang, B., Qin, J., Wu, K. & Jiang, F. (2022). Physical, structural, and water barrier properties of emulsified blend film based on konjac glucomannan/agar/gum Arabic incorporating virgin coconut oil. Lwt, 154, 112683. https://doi.org/10.1016/j.lwt.2021.112683.
Yang, R., Miao, J., Shen, Y., Cai, N., Wan, C., Zou, L., Chen, C. & Chen, J. (2021). Antifungal effect of cinnamaldehyde, eugenol and carvacrol nanoemulsion against Penicillium digitatum and application in postharvest preservation of citrus fruit, LWT, 141.
Zacarías-García, J., Cronje, P. J., Diretto, G., Zacarías, L. & Rodrigo, M. J. (2022). A comprehensive analysis of carotenoids metabolism in two red-fleshed mutants of Navel and Valencia sweet oranges (Citrus sinensis). Frontiers in Plant Science, 13(October), 1 - 24. https://doi.org/10.3389/fpls.2022.1034204.
Zhang, K., Yang, W., Ge, F., Xu, B., Chen, Y., Yin, X., Liu, Y. & Zuo, H. (2020). A self-curing konjac glucomannan/CaCO3 coating for corrosion protection of AA5052 aluminum alloy in NaCl solution. International Journal of Biological Macromolecules, 151, 691 - 701. https://doi.org/10.1016/j.ijbiomac.2020.02.223.
Zia, H., Murray, H., Hofsommer, M., Barreto, A. M., Pavon-vargas, D., Puzovic, A., Gędas, A., Rincon, S., Gössinger, M. & Slatnar, A. (2025). Comparing the impact of conventional and non-conventional processing technologies on water-soluble vitamins and color in strawberry nectar – a pilot scale study. Food Chemistry, 463(August 2024). https://doi.org/10.1016/j.foodchem.2024.141078.

Date published: 2026-04-29

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